xref: /openbmc/linux/arch/m68k/include/asm/pgtable_mm.h (revision 82e6fdd6)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _M68K_PGTABLE_H
3 #define _M68K_PGTABLE_H
4 
5 #include <asm-generic/4level-fixup.h>
6 
7 #include <asm/setup.h>
8 
9 #ifndef __ASSEMBLY__
10 #include <asm/processor.h>
11 #include <linux/sched.h>
12 #include <linux/threads.h>
13 
14 /*
15  * This file contains the functions and defines necessary to modify and use
16  * the m68k page table tree.
17  */
18 
19 #include <asm/virtconvert.h>
20 
21 /* Certain architectures need to do special things when pte's
22  * within a page table are directly modified.  Thus, the following
23  * hook is made available.
24  */
25 #define set_pte(pteptr, pteval)					\
26 	do{							\
27 		*(pteptr) = (pteval);				\
28 	} while(0)
29 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
30 
31 
32 /* PMD_SHIFT determines the size of the area a second-level page table can map */
33 #ifdef CONFIG_SUN3
34 #define PMD_SHIFT       17
35 #else
36 #define PMD_SHIFT	22
37 #endif
38 #define PMD_SIZE	(1UL << PMD_SHIFT)
39 #define PMD_MASK	(~(PMD_SIZE-1))
40 
41 /* PGDIR_SHIFT determines what a third-level page table entry can map */
42 #ifdef CONFIG_SUN3
43 #define PGDIR_SHIFT     17
44 #elif defined(CONFIG_COLDFIRE)
45 #define PGDIR_SHIFT     22
46 #else
47 #define PGDIR_SHIFT	25
48 #endif
49 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
50 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
51 
52 /*
53  * entries per page directory level: the m68k is configured as three-level,
54  * so we do have PMD level physically.
55  */
56 #ifdef CONFIG_SUN3
57 #define PTRS_PER_PTE   16
58 #define __PAGETABLE_PMD_FOLDED
59 #define PTRS_PER_PMD   1
60 #define PTRS_PER_PGD   2048
61 #elif defined(CONFIG_COLDFIRE)
62 #define PTRS_PER_PTE	512
63 #define __PAGETABLE_PMD_FOLDED
64 #define PTRS_PER_PMD	1
65 #define PTRS_PER_PGD	1024
66 #else
67 #define PTRS_PER_PTE	1024
68 #define PTRS_PER_PMD	8
69 #define PTRS_PER_PGD	128
70 #endif
71 #define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
72 #define FIRST_USER_ADDRESS	0UL
73 
74 /* Virtual address region for use by kernel_map() */
75 #ifdef CONFIG_SUN3
76 #define KMAP_START     0x0DC00000
77 #define KMAP_END       0x0E000000
78 #elif defined(CONFIG_COLDFIRE)
79 #define KMAP_START	0xe0000000
80 #define KMAP_END	0xf0000000
81 #else
82 #define	KMAP_START	0xd0000000
83 #define	KMAP_END	0xf0000000
84 #endif
85 
86 #ifdef CONFIG_SUN3
87 extern unsigned long m68k_vmalloc_end;
88 #define VMALLOC_START 0x0f800000
89 #define VMALLOC_END m68k_vmalloc_end
90 #elif defined(CONFIG_COLDFIRE)
91 #define VMALLOC_START	0xd0000000
92 #define VMALLOC_END	0xe0000000
93 #else
94 /* Just any arbitrary offset to the start of the vmalloc VM area: the
95  * current 8MB value just means that there will be a 8MB "hole" after the
96  * physical memory until the kernel virtual memory starts.  That means that
97  * any out-of-bounds memory accesses will hopefully be caught.
98  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
99  * area for the same reason. ;)
100  */
101 #define VMALLOC_OFFSET	(8*1024*1024)
102 #define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
103 #define VMALLOC_END KMAP_START
104 #endif
105 
106 /* zero page used for uninitialized stuff */
107 extern void *empty_zero_page;
108 
109 /*
110  * ZERO_PAGE is a global shared page that is always zero: used
111  * for zero-mapped memory areas etc..
112  */
113 #define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
114 
115 /* number of bits that fit into a memory pointer */
116 #define BITS_PER_PTR			(8*sizeof(unsigned long))
117 
118 /* to align the pointer to a pointer address */
119 #define PTR_MASK			(~(sizeof(void*)-1))
120 
121 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
122 /* 64-bit machines, beware!  SRB. */
123 #define SIZEOF_PTR_LOG2			       2
124 
125 extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);
126 
127 /*
128  * The m68k doesn't have any external MMU info: the kernel page
129  * tables contain all the necessary information.  The Sun3 does, but
130  * they are updated on demand.
131  */
132 static inline void update_mmu_cache(struct vm_area_struct *vma,
133 				    unsigned long address, pte_t *ptep)
134 {
135 }
136 
137 #endif /* !__ASSEMBLY__ */
138 
139 #define kern_addr_valid(addr)	(1)
140 
141 /* MMU-specific headers */
142 
143 #ifdef CONFIG_SUN3
144 #include <asm/sun3_pgtable.h>
145 #elif defined(CONFIG_COLDFIRE)
146 #include <asm/mcf_pgtable.h>
147 #else
148 #include <asm/motorola_pgtable.h>
149 #endif
150 
151 #ifndef __ASSEMBLY__
152 /*
153  * Macro to mark a page protection value as "uncacheable".
154  */
155 #ifdef CONFIG_COLDFIRE
156 # define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | CF_PAGE_NOCACHE))
157 #else
158 #ifdef SUN3_PAGE_NOCACHE
159 # define __SUN3_PAGE_NOCACHE	SUN3_PAGE_NOCACHE
160 #else
161 # define __SUN3_PAGE_NOCACHE	0
162 #endif
163 #define pgprot_noncached(prot)							\
164 	(MMU_IS_SUN3								\
165 	 ? (__pgprot(pgprot_val(prot) | __SUN3_PAGE_NOCACHE))			\
166 	 : ((MMU_IS_851 || MMU_IS_030)						\
167 	    ? (__pgprot(pgprot_val(prot) | _PAGE_NOCACHE030))			\
168 	    : (MMU_IS_040 || MMU_IS_060)					\
169 	    ? (__pgprot((pgprot_val(prot) & _CACHEMASK040) | _PAGE_NOCACHE_S))	\
170 	    : (prot)))
171 
172 #endif /* CONFIG_COLDFIRE */
173 #include <asm-generic/pgtable.h>
174 #endif /* !__ASSEMBLY__ */
175 
176 /*
177  * No page table caches to initialise
178  */
179 #define pgtable_cache_init()	do { } while (0)
180 
181 #define check_pgt_cache()	do { } while (0)
182 
183 #endif /* _M68K_PGTABLE_H */
184